Various detection techniques and methods based on thermal sensing exist and well-known in the art. Certain methods employ thermocouple, thermopile or infrared sensors, as in U.S. Pat. No. 6,909,093, and in U.S. Pat. No. 6,402,369. Alternatively, some of the methods employ charged coupled devices, as disclosed in U.S. Pat. No. 5,466,348. Several other approaches employ pyroelectric sensors, as in U.S. Pat. No. 4,829,003, and in U.S. Pat. No. 5,108,576.
Thermal sensing is employed in diversified applications and for versatile purposes. Thus, U.S. Pat. No. 4,829,003 discloses a method of detecting enzymes or enzymatic substrates in a liquid or gas stream, by the heat generated upon their interactions, using pyroelectric sensor. U.S. Pat. No. 5,108,576 further suggests employing the pyroelectric sensor for detecting the binding of antigens by antibodies as well as enzyme-substrate and enzyme-coenzyme interactions. Tannenbaum et al., in U.S. Pat. No. 3,878,049 disclose a method for quantitative measurement of concentrations of various reactants, by measuring the heat produced when they metabolized by enzymes or microorganisms.
Various techniques have been used to determine whether a chemical interaction has occurred between two reactants. One example of prior art is the use of micro-cantilevers carrying copies of certain molecule on their tip for detecting possible conjugates in a sample, as disclosed in U.S. Pat. No. 6,203,983. Another example of prior art is the use of fluorescence dyes or other radiative molecules to detect the event of DNA hybridization, or binding between antibodies and their target proteins, disclosed in U.S. Pat. No. 5,578,832, and in U.S. Pat. No. 5,631,734. In these inventions a probe is deposited on a slide and than allowed to hybridize with a sample that carries labeled DNA or proteins. The probe bound labeled molecules are than detected using an optical system.